Yeah your sticker's fine. Even though I would not vote for Romney. I look at that and think "ok, he likes Romney". It's adult, it's clearly a sticker to support your choice in the upcoming election. It's probably not going to upset anyone. But the other one says "you're stupid" to roughly 50% of the populace. It's juvenile... it's one thing to see it on a 96 corolla, it's another to see it on a 360 Modena.
To the guy that is unemployed and sees Romney and the republicans as part of the problem not the solution, the last thing he wants to see is a guy driving a Ferrari, calling him stupid. It's just asking for trouble. If he just had a sticker like you that said Romney, he'd be taking a lot less risk.